This invention relates to audio recording/reproducing apparatus and, more particularly, to a digital dictation system permitting simultaneous dictation and transcription of the same message from a central store and, furthermore, to permit the store to be accessed by way of a port which normally enables transcribe operations to be carried out but which may be conditioned for operation as a dictate port.
In typical prior art dictation systems, audio information is recorded on a magnetic medium, typically magnetic tape. Typical of such dictation equipment are analog recorders wherein the audio information is recorded in analog form. Customarily, analog dictation systems have been classified as stand alone units, also known as desk-top or portable recorders in which the magnetic tape is housed in a replaceable tape cassette, central systems wherein one or more bins of endless tape are accessible to several dictators and to several transcriptionists, whereby multiple dictate and transcribe operations may be performed simultaneously, central systems wherein individual tape decks are used in place of the aforementioned tape bins, and so-called small work group systems which combine the advantages of both central and stand alone dictation systems. Each of the aforementioned types of equipment has been made available by Dictaphone Corporation, the assignee of the present invention, and descriptions of typical apparatus are found in the following patent literature:
Stand alone machines are described in U.S. Pat. Nos. 4,378,577 and 4,410,923.
Central systems using endless magnetic tape as the recording medium are described in U.S. Pat. Nos. 3,817,436 and 3,984,644.
Central systems using replaceable tape cassettes are described in U.S. Pat. Nos. 4,092,679 and 4,636,888.
Small work group systems are described in U.S. Ser. No. 145,228, filed Jan. 19, 1988 and U.S. Ser. No. 799,909, filed Nov. 20, 1985.
Recently, digital recording techniques have been proposed for use in dictation equipment. Although digital controls have long been used in controlling and monitoring dictation and transcription operations, such as described in U.S. Pat. Nos. 4,319,337 and 4,623,988, the audio information recorded in such digitally controlled equipment nevertheless has been recorded in analog form. However, with the recent development of low cost, high capacity digital storage equipment, such as high capacity floppy disks and, more advantageously, high capacity hard disk storage systems (also known as Winchester disk drives, rigid disk drives, disk packs, etc.), the opportunity to economically record audio; information in digital form has been made available.
In digital dictation equipment, input analog audio signals are sampled and each analog sample is converted to a digital audio sample. Bytes representing the digital audio samples are recorded on a magnetic disk, either a floppy disk or a Winchester disk, in much the same way as any other digital information is magnetically stored (or "written"). During playback (or "reading"), each byte is read from the magnetic disk and converted to an analog sample. Successive samples result in a restoration of the original analog audio signal. The high speeds at which digital signals are processed, recorded, read and manipulated when compared to the relatively low frequencies of typical speech signals, permit a relatively inexpensive digital storage device to be used as the primary store of a central dictation system. By using a single (or relatively few) high capacity Winchester disk drive, several dictators and several transcriptionists may access the central store to record and transcribe messages. Also, digit al recording techniques permit quick access, on the order of milliseconds, to virtually any message that has been recorded, thereby facilitating quick review, recovery and editing of respective messages. Indeed, contrary to typical analog dictation systems, a digital system permits a dictator to edit a message in such a way that, during subsequent transcription of that edited message, the transcriptionist need not even be aware of the fact that editing has been achieved. This contrasts with conventional analog dictation systems wherein editing typically is achieved by recording special instructions to direct a transcriptionist to other parts of the magnetic tape on which inserts or other changes are recorded.
Central dictation systems permit a transcriptionist to begin transcription of a message, such as a letter, even while the dictator continues to record the remainder of that letter. Digital dictation equipment facilitates such simultaneous dictate/transcribe operations; and since magnetic tape is not used as the record medium, there is no physical constraint to prevent the transcriptionist from transcribing information which has been recorded by the dictator only milliseconds before. Hence, by eliminating separate dictate and transcribe heads separated by a finite distance, as was required in central dictation systems employing magnetic tape, there is no physical impediment to keep the transcriptionist from transcribing "right on the heels" of the dictator. Indeed, by using digital dictation equipment, it is possible for the dictator to review that portion of his message which has already been transcribed.
Heretofore, the fact that a dictator could not access any portion of a message which had been transcribed prevented the dictator from reviewing that message, modifying it and improving it as he may desire. Such ability now is present in digital dictation equipment. However, a problem may arise if the dictator revises a previously transcribed message without apprising the transcriptionist of such revisions.
Although central dictation systems, both of the analog magnetic tape type and the digital type, accommodate several dictators and transcriptionists, there is a physical limitation based simply on the number of physical connections that may be made at one time to the system. In a digital dictation system, such connections are made through "ports"; and it is common to provide a number of dictate ports as well as a number of transcribe ports. Since a transcriptionist may gain access to any message that has been recorded in the digital dictation system, it often suffices to provide far fewer transcribe ports than dictate ports.
At times, a central dictation system may be subject to heavy usage, or dictation traffic. As a result, a greater number of dictators may desire access to the system than may be accommodated. By providing one or more dedicated transcribe ports, dictators have been resigned to awaiting the availability of a dictate port before system access, or seizure, may begin.